Pull Request validation by multiple jenkins - webhook name configuration

I would like to have one PR validation per repo Webhook linked to a different Jenkins instance

The current behavior is as follows:

1.- Once Multibranch Pipeline is saved, scm api creates automatically the webhook for you... So under this repo Webhooks is set multiple webhooks per each of your masters (with their respective endpoints).

2.- Once a developer makes a new PR the build is launched in each of the masters... but just one validation (continuous-integration/jenkins/pr-merge) is happening for the repo. The last webhook which was joined to the repo.